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PLoS Neglected Tropical Diseases Nov 2023In Bangladesh, preventive chemotherapy targeting soil-transmitted helminth (STH) infections in school-age children has been implemented since 2008. To evaluate the...
BACKGROUND
In Bangladesh, preventive chemotherapy targeting soil-transmitted helminth (STH) infections in school-age children has been implemented since 2008. To evaluate the success of this strategy, surveys were conducted between 2017 and 2020 in 10 out of 64 districts. We estimate the geographic distribution of STH infections by species at high spatial resolution, identify risk factors, and estimate treatment needs at different population subgroups.
METHODOLOGY
Bayesian geostatistical models were fitted to prevalence data of each STH species. Climatic, environmental, and socioeconomic predictors were extracted from satellite images, open-access, model-based databases, and demographic household surveys, and used to predict the prevalence of infection over a gridded surface at 1 x 1 km spatial resolution across the country, via Bayesian kriging. These estimates were combined with gridded population data to estimate the number of required treatments for different risk groups.
PRINCIPAL FINDINGS
The population-adjusted prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm across all ages is estimated at 9.9% (95% Bayesian credible interval: 8.0-13.0%), 4.3% (3.0-7.3%), and 0.6% (0.4-0.9%), respectively. There were 24 out of 64 districts with an estimated population-adjusted STH infection prevalence above 20%. The proportion of households with improved sanitation showed a statistically important, protective association for both, A. lumbricoides and T. trichiura prevalence. Precipitation in the driest month of the year was negatively associated with A. lumbricoides prevalence. High organic carbon concentration in the soil's fine earth fraction was related to a high hookworm prevalence. Furthermore, we estimated that 30.5 (27.2; 36.0) million dosages of anthelmintic treatments for school-age children were required per year in Bangladesh.
CONCLUSIONS/SIGNIFICANCE
For each of the STH species, the prevalence was reduced by at least 80% since treatment was scaled up more than a decade ago. The current number of deworming dosages could be reduced by up to 61% if the treatment strategy was adapted to the local prevalence.
Topics: Child; Animals; Humans; Soil; Bayes Theorem; Bangladesh; Helminthiasis; Hookworm Infections; Helminths; Ancylostomatoidea; Ascaris lumbricoides; Prevalence; Feces
PubMed: 37930980
DOI: 10.1371/journal.pntd.0011656 -
International Journal For Parasitology.... Dec 2023Intestinal parasitic infections such as amoebiasis, ascariasis, hookworm infection, and are the most common infections among non-human primates (NHPs). There are always...
Intestinal parasitic infections such as amoebiasis, ascariasis, hookworm infection, and are the most common infections among non-human primates (NHPs). There are always the possibilities of transmission these parasites between humans and NHPs. Multiple groups of rhesus macaques () live in the urban area of Kathmandu Valley near human settlements, however the gastrointestinal (GI) parasitic infections in those macaques are understudied. This study aimed to explore the GI parasites in free-ranging macaques from Pashupatinath, Swayambhunath, Tripureshwor, Nilbarahi temples and a group of captive rhesus macaques in the Central Zoo, Kathmandu. Fecal samples were collected from the macaques between October 2021 to September 2022 and assessed for parasites by the both wet mount method and concentration technique. There is high prevalence of GI parasite infection; out of 121 fecal samples examined, 87.6% of samples were positive. Six species of protozoans and eight species of helminths were identified from the fecal samples including the first report of in monkeys of Nepal. Among the protozoan parasites, (54.71%) showed the highest prevalence followed by (44.33%), (19.81%), and (10%). Among the helminths, spp. (31.13%) and spp. (31.13%) showed the highest prevalence followed by Hookworm (24.52%), and spp. (23.58%) The likelihood ratio test suggested that the prevalence differed significantly with the seasons for , spp., spp., Hookworm, and spp. The prevalence of , , spp. spp. and Unknown spp.1 differed with sampling localities. The high prevalence of GI parasites found in the macaques living in the densely urbanized Kathmandu presents a potential threat to humans and warrants further study as well as increased education of the public and management of the human-macaque interface in the urban landscape of the Valley.
PubMed: 37915770
DOI: 10.1016/j.ijppaw.2023.10.007 -
PLoS Neglected Tropical Diseases Nov 2023Neglected tropical diseases (NTDs) affect most impoverished communities in developing countries, like Myanmar in Southeast Asia. NTDs have been understudied and...
BACKGROUND
Neglected tropical diseases (NTDs) affect most impoverished communities in developing countries, like Myanmar in Southeast Asia. NTDs have been understudied and underreported in Myanmar.
METHODS
A systematic review of published and grey literature (1900-2023) on neglected tropical diseases (NTDs) in Myanmar was conducted. The literature search included five international databases: PubMed, EMBASE, Ovid Global Health, and Web of Science Core Collection and one national database: the Myanmar Central Biomedical Library (locally published papers and grey literature). The selection criteria included articles with all types of study designs of current or previous infections conducted in humans, that reported NTDs, recognised by WHO, US CDC, and listed in PLoS NTDs. We included melioidosis and rickettsioses which we consider also meet the definition of an NTD.
RESULTS
A total of 5941 records were retrieved and screened, of which, 672 (11%) met the selection criteria and were included in this review. Of the included articles, 449 (65%) were published after 2000 and 369 (55%) were from two regions (Yangon and Mandalay) of Myanmar. Of the included articles, 238 (35%) reported bacterial NTDs, 212 (32%) viral NTDs, 153 (23%) helminth NTDs, 25 (4%) protozoal NTDs and 39 (6%) reported more than one aetiology. Based on reported frequency in descending order, the bacterial NTDs were leprosy, Escherichia coli enteritis, salmonellosis, cholera, shigellosis, melioidosis, leptospirosis and rickettsioses; the viral NTDs were dengue, chikungunya and Japanese encephalitis virus (JEV) infection; the protozoal NTDs were amoebiasis, giardiasis and leishmaniasis, and the helminth NTDs were ascariasis, trichuriasis, hookworm disease, filariasis and strongyloidiasis.
CONCLUSION
This review summarises NTDs reported in Myanmar over the past 100 years. The findings suggest that most NTDs are likely to be under reported, especially from the majority of the country which is far from academic centres. Research capacity building together with strengthening of laboratory systems would lead to better understanding of the true burden of NTDs in Myanmar.
TRIAL REGISTRATION
PROSPERO registration ID: CRD42018092627.
Topics: Animals; Humans; Myanmar; Melioidosis; Ascariasis; Helminths; Neglected Diseases; Tropical Medicine; Encephalitis, Japanese; Rickettsia Infections
PubMed: 37910592
DOI: 10.1371/journal.pntd.0011706 -
Anais Da Academia Brasileira de Ciencias 2023Enteroparasites are an important public health problem and the treatment seeks to cure and reduce transmission. The aim of this study was to evaluate the therapeutic...
Enteroparasites are an important public health problem and the treatment seeks to cure and reduce transmission. The aim of this study was to evaluate the therapeutic efficacy of anthelmintic treatment in individuals living in a rural community area in Camamu, Bahia, Brazil. The parasitological diagnosis was performed by spontaneous sedimentation, Baermann-Moraes and Agar Plate Culture methods. A total of 212 individuals were evaluated. The most frequent helminth was Trichuris trichiura, 24.5% (52/212), followed by Ascaris lumbricoides, 21.2% (45/212), hookworms, 16.5% (35/212), and S. stercoralis, 4.7% (10/212). In the anthelmintic treatment follow up, T. trichiura infection presented the lowest parasitological cure rate, only 60.6% (20/33). Hookworm, Ascaris lumbricoides and Strongyloides stercoralis infections demonstrated cure rates of 70.5 (12/17), 78.1 (25/32) and 100% (5/5), respectively. Individuals who remained infected underwent a new drug therapy. The second parasitological cure rate for T. trichiura was 38.5% (5/13), and 66.7% (2/3) and 75% (3/4) for hookworms and Ascaris lumbricoides, respectively. Trichuris trichiura infection presented the lowest parasitological cure rate at this second evaluation. This reinforces the need to perform a follow-up of all treated individuals. The possibility of drug resistance denotes the necessity for studies to clarify the mechanisms and to evaluate new therapeutic approaches.
Topics: Animals; Humans; Follow-Up Studies; Brazil; Rural Population; Anthelmintics; Hookworm Infections; Ancylostomatoidea; Ascaris lumbricoides; Feces; Prevalence
PubMed: 37909545
DOI: 10.1590/0001-3765202320230323 -
Vaccine Oct 2023Hookworm, a parasitic infection, retains a considerable burden of disease, affecting the most underprivileged segments of the general population in endemic countries and...
Hookworm, a parasitic infection, retains a considerable burden of disease, affecting the most underprivileged segments of the general population in endemic countries and remains one of the leading causes of mild to severe anemia in Low and Middle Income Countries (LMICs), particularly in pregnancy and children under 5. Despite repeated large scale Preventive Chemotherapy (PC) interventions since more than 3 decades, there is broad consensus among scholars that elimination targets set in the newly launched NTD roadmap will require additional tools and interventions. Development of a vaccine could constitute a promising expansion of the existing arsenal against hookworm. Therefore, we have evaluated the biological and implementation feasibility of the vaccine development as well as the added value of such a novel tool. Based on pipeline landscaping and the current knowledge on key biological aspects of the pathogen and its interactions with the host, we found biological feasibility of development of a hookworm vaccine to be moderate. Also, our analysis on manufacturing and regulatory issues as well as potential uptake yielded moderate implementation feasibility. Modelling studies suggest a that introduction of a vaccine in parallel with ongoing integrated interventions (PC, WASH, shoe campaigns), could substantially reduce burden of disease in a cost - saving mode. Finally a set of actions are recommended that might impact positively the likelihood of timely development and introduction of a hookworm vaccine.
PubMed: 37863671
DOI: 10.1016/j.vaccine.2023.05.013 -
Tropical Parasitology 2023The complex life cycle of geohelminth parasites make it difficult to manage repeated infections that occur in endemic areas, that requires the development of new...
BACKGROUND
The complex life cycle of geohelminth parasites make it difficult to manage repeated infections that occur in endemic areas, that requires the development of new therapeutic strategies. Human hookworm . and . are a serious problem in many areas of the world where the old age anti-helminthics are ineffective. To address this, we have tried a non-traditional therapeutic approach for a sustainable solution to manage parasite infections.
AIMS AND OBJECTIVES
In this study, we attempted to develop a new type of therapy using value-added probiotics-producing antiparasitic RNA interference (RNAi) molecules against a vital hookworm ( sp.) enzyme, astacin-like metalloprotease -MTP-1. A new gut delivery RNAi vector was designed to produce double-stranded RNA (dsRNA) against the target to be delivered by feeding with a probiotic lactis that when administered in endemic areas can potentially be used to control the spread of infection by interrupting the life cycle of hookworm.
RESULTS
The engineered probiotics colonizing the gut, when consumed by the parasite released the dsRNA that which knocked down the target by RNAi interfering with their moulting and tissue migration. The initial penetration of the larvae into the gut lining was reduced by 70%, followed by a reduction of up to 50% in migration to the critical organs. The damage caused to the liver (30%-40%) and the kidneys (50%-60%) by the hookworm in mouse models as quantitated by enzymes released in the blood was totally reversed when the worms were pre fed with the engineered L. lactis before the parasite challenge.
CONCLUSIONS
We believe that this is the first demonstrated knockdown of a target gene in hookworms using probiotics genetically engineered to stimulate RNAi (RNAi food), administered through the oral route. This novel method of parasite control when extended to other hookworms, and can augment the efficacy of the existing anthelminthics if combined with them.
PubMed: 37860612
DOI: 10.4103/tp.tp_74_22 -
The Lancet Regional Health. Western... Dec 2023Soil-transmitted helminth (STH) infection control programs typically consist of school-based preventive chemotherapy (PC) targeted to school-aged children. STH...
Community-wide versus school-based targeted deworming for soil-transmitted helminth control in school-aged children in Vietnam: the CoDe-STH cluster-randomised controlled trial.
BACKGROUND
Soil-transmitted helminth (STH) infection control programs typically consist of school-based preventive chemotherapy (PC) targeted to school-aged children. STH reservoirs in untreated community members contribute to ongoing transmission in children. The CoDe-STH (Community Deworming against STH) trial, conducted in Dak Lak province, Vietnam, between October 2019 and November 2020, aimed to determine whether community-wide mass drug administration (MDA) is more effective than school-based targeted PC in reducing STH prevalence and intensity in children.
METHODS
In this two-arm cluster randomised controlled trial, 64 primary schools were randomly assigned 1:1 to receive either school-based targeted PC ("school arm") or community-wide MDA ("community arm"). A single dose of albendazole 400 mg was used for deworming. The primary outcome was hookworm prevalence in schoolchildren, measured using quantitative real-time PCR. We also measured infection intensity for only, using qPCR cycle threshold (Ct) values converted into eggs per gram of faeces (EPG). Analysis was by intention to treat. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12619000309189).
FINDINGS
The analysis included 4955 children in the school arm and 5093 children in the community arm. was the dominant STH species. The relative reduction in hookworm prevalence was not significantly different between the school arm (30.1%, 95% confidence interval [CI] 20.5-36.9) and the community arm (34.6%, 95% CI 19.9-49.4). Due to lower baseline prevalence than expected, the study was underpowered to detect a difference in prevalence reduction between the study arms. The community arm showed significantly greater relative reduction in infection intensity (56.0%, 95% CI 39.9-72.1) compared to the school arm (3.4%, 95% CI -24.7 to 31.4). The community arm also showed greater relative reduction in prevalence of moderate-to-heavy intensity (≥2000 EPG) infections (81.1%; 95% CI 69.7-92.6) compared to the school arm (39.0%, 95% CI 13.7-64.2).
INTERPRETATION
Although no impact was seen on overall prevalence, community-wide MDA was more effective in lowering infection intensity in schoolchildren compared to school-based targeted PC, measured 12 months after one round of albendazole deworming with high coverage.
FUNDING
National Health and Medical Research Council, Australia (APP1139561).
PubMed: 37860203
DOI: 10.1016/j.lanwpc.2023.100920 -
The Lancet Regional Health. Western... Dec 2023School-based targeted preventive chemotherapy (PC), the main strategy for soil-transmitted helminths (STH) control, excludes other at-risk populations including adults...
Cost and cost-effectiveness analysis of mass drug administration compared to school-based targeted preventive chemotherapy for hookworm control in Dak Lak province, Vietnam.
BACKGROUND
School-based targeted preventive chemotherapy (PC), the main strategy for soil-transmitted helminths (STH) control, excludes other at-risk populations including adults and preschool children. Mass drug administration (MDA), covering all age groups, would bring additional health benefits but also requires greater investment. This cost survey and cost-effectiveness analysis compared MDA with school-based targeted PC for STH control in Dak Lak, Vietnam, where STH are endemic.
METHODS
A cost survey was conducted in 2020 to estimate the total and per person economic and financial cost of each strategy. Monte Carlo simulation accounted for uncertainty in cost estimates. The primary effectiveness measure was hookworm-related disability-adjusted life years (DALYs) averted, and secondary measures were hookworm infection-years averted and moderate-to-heavy intensity hookworm infection-years averted. A Markov model was used to determine the incremental cost-effectiveness ratio (ICER) of MDA compared to school-based targeted PC using a government payer perspective and a ten-year time horizon. One-way and probabilistic sensitivity analyses (PSA) were performed. Costs are reported in 2020 USD ($).
FINDINGS
The economic cost per person was $0.27 for MDA and $0.43 for school-based targeted PC. MDA in Dak Lak will cost $472,000 per year, while school-based targeted PC will cost $117,000. Over 10 years, MDA is estimated to avert an additional 121,465 DALYs; 4,019,262 hookworm infection-years, and 765,844 moderate-to-heavy intensity hookworm infection-years compared to school-based targeted PC. The ICER was $28.55 per DALY averted; $0.87 per hookworm infection-years averted, and $4.54 per moderate-to-heavy intensity hookworm infection-years averted. MDA was cost-effective in all PSA iterations.
INTERPRETATION
In areas where hookworm predominates and adults suffer a significant burden of infection, MDA is cost effective compared to school based targeted PC and is the best strategy to achieve global targets.
FUNDING
The project was funded by the National Health and Medical Research Council (NHMRC) of Australia (Project Grant APP1139561) and JPCDT was supported by a UNSW Scientia PhD Scholarship.
PubMed: 37860202
DOI: 10.1016/j.lanwpc.2023.100913 -
PLoS Neglected Tropical Diseases Oct 2023The Geshiyaro project aims to assess the feasibility of interrupting transmission of soil-transmitted helminths (STH) and schistosome (SCH) infection in the Wolaita zone...
Baseline soil-transmitted helminth and schistosome infection in the Geshiyaro project, Ethiopia: A unique transmission interruption project using biometric fingerprinting for longitudinal individual analysis.
BACKGROUND
The Geshiyaro project aims to assess the feasibility of interrupting transmission of soil-transmitted helminths (STH) and schistosome (SCH) infection in the Wolaita zone of southern Ethiopia through high coverage community-wide mass drug administration (MDA), in combination with improved water, sanitation, and hygiene services and behaviour change communication delivered through the existing health care infrastructure. To accurately measure treatment coverage a population census was conducted enrolling individuals with biometric fingerprinting and barcoded ID cards. This paper details the baseline census and parasitology surveys conducted before the start of any interventions.
METHODS
The census was conducted in five of the 15 Wolaita districts between October 2018 and December 2019, enrolling all consenting participants from every household. Simultaneously, a cross-sectional parasitology survey was conducted in 130 out of 361 randomly selected communities from all 15 districts, with 100 individuals across all age groups (infant to adult) per community providing stool and urine for analysis by duplicate Kato-Katz and a point-of-care circulating cathodic antigen (POC-CCA) to test for Schistosoma mansoni and STH, and microhaematuria and urine filtration for Schistosoma haematobium. Of the 130 communities, 30 were randomly selected for annual, longitudinal parasitological monitoring, with 150 randomly selected individuals from infant to adult providing two days of stool and urine samples for analysis by the same diagnostic tests per community.
RESULTS
In total 97,919 households participated in the baseline census enrolling 466,071 individuals, with parasitological data obtained from 10,785 people. At baseline, 15.5% were infected with at least one STH species, with Ascaris lumbricoides (9.5%), followed by hookworm (7.2%) and Trichuris trichiura (1.8%). Substantial heterogeneity in STH prevalence was observed between communities ranging from 0% to 61% where most infections were low intensity. Schistosoma mansoni infection was the dominant schistosome infection (0.85% by Kato-Katz and 13.3% by POC-CCA trace negative and 21.5% trace positive), with few Schistosoma haematobium infections identified (2.77% haematuria positive and 0.13% positive by urine filtration).
CONCLUSIONS
While the national control program in Ethiopia has made good progress in reducing prevalence of STH and SCH in Wolaita since it was launched in 2015, there remain areas of persistent infection suggesting the existence of environmental or behavioural risk factors that contribute to ongoing transmission. This project aims to identify the most efficient intervention strategies to reduce community burden and reach interruption of transmission.
Topics: Animals; Humans; Helminthiasis; Soil; Ethiopia; Cross-Sectional Studies; Helminths; Schistosoma mansoni; Feces; Biometry; Prevalence
PubMed: 37851666
DOI: 10.1371/journal.pntd.0011589 -
Saudi Journal of Biological Sciences Nov 2023Ascariasis and intestinal parasitic nematodes are the leading cause of mass mortality infecting many people across the globe. In light of the various deleterious side... (Review)
Review
Ascariasis and intestinal parasitic nematodes are the leading cause of mass mortality infecting many people across the globe. In light of the various deleterious side effects of modern chemical-based allopathic drugs, our preferences have currently shifted towards the use of traditional plant-based drugs or botanicals for treating diseases. The defensive propensities in the botanicals against parasites have probably evolved during their co-habitation with parasites, humans and plants in nature and hence their combative interference in one another's defensive mechanisms has occurred naturally ultimately being very effective in treating diseases. This article broadly outlines the utility of plant-based compounds or botanicals prepared from various medicinal herbs that have the potential to be developed as effective therapies against the important parasites causing ascariasis and intestinal hookworm infections leading to ascariasis & infections and thereby human mortality, wherein allopathic treatments are less effective and causes enormous side-effects.
PubMed: 37841664
DOI: 10.1016/j.sjbs.2023.103814